Java后增量器的行为
为什么上面的代码打印1？我听说a++意味着你将得到a的值。然后增加它。但是上面的代码从未增加a，只是打印了1。有人能解释一下这里发生了什么吗？Java后增量器的行为,java,post-increment,Java,Post Increment,为什么上面的代码打印1？我听说a++意味着你将得到a的值。然后增加它。但是上面的代码从未增加a，只是打印了1。有人能解释一下这里发生了什么吗？intb=a++相当于intb=a；a+=1。打印b时，a==2&&b==1intb=a++相当于intb=a；a+=1。当您打印b，a==2&&b==1时，它会按预期工作；下面是解释的代码： public static void main(String[] args) { int a = 1; int b = a++;
intb=a++intb=a；a+=1ba==2&&b==1intb=a++intb=a；a+=1ba==2&&b==1 public static void main(String[] args) {
int a = 1;
int b = a++;
System.out.println(b);
}
public static void main(String[] args) {
// a is assigned the value 1
int a = 1;
// b is assigned the value of a (1) and THEN a is incremented.
// b is now 1 and a is 2.
int b = a++;
System.out.println(b);
// if you had printed a here it would have been 2
}
它按预期工作；下面是解释的代码：
public static void main(String[] args) {
int a = 1;
int b = a++;
System.out.println(b);
}
public static void main(String[] args) {
// a is assigned the value 1
int a = 1;
// b is assigned the value of a (1) and THEN a is incremented.
// b is now 1 and a is 2.
int b = a++;
System.out.println(b);
// if you had printed a here it would have been 2
}
a++aab=a++b=1a=2b=++ab=2++a递增，然后赋值
a++aab=a++b=1a=2b=++ab=2++a递增，然后赋值
增量后含义=第一次完成分配，然后增量。 增量前含义=第一次增量，然后分配 例：
The reason is is as follow.
If it is i++, then equalent code is like this.
result = i;
i = i+1;
return result
If it is ++i. then the equlent code is like this.
i=i+1;
result =i;
return i
So considering your case, even though the value of i is incremented, the returned value is old value. (Post increment)
增量后含义=第一次完成分配，然后增量。 增量前含义=第一次增量，然后分配 例：
The reason is is as follow.
If it is i++, then equalent code is like this.
result = i;
i = i+1;
return result
If it is ++i. then the equlent code is like this.
i=i+1;
result =i;
return i
So considering your case, even though the value of i is incremented, the returned value is old value. (Post increment)
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